Inspired from changelog-check-action

.github/workflows/changelog.yml

@@ -7,21 +7,18 @@ on:
     types: [opened, reopened, synchronize]
 
 jobs:
+  # CI job heavily inspired by: https://github.com/tarides/changelog-check-action
   changelog:
     runs-on: ubuntu-latest
+    using: "composite"
     steps:
       - name: Checkout code
         uses: actions/checkout@main
         with:
           fetch-depth: 0
-      - name: Check if CHANGELOG.md is modified
-        run: |
-          # Get the list of changed files in the PR
-          changed_files=$(git diff --name-only origin/${{ github.event.pull_request.base.ref }}...${{ github.sha }})
-          # Check if CHANGELOG.md is in the list of changed files
-          if echo "$changed_files" | grep -q '^CHANGELOG.md$'; then
-            echo "CHANGELOG.md has been modified."
-          else
-            echo $'::warning file=CHANGELOG.md::CHANGELOG.md has not been modified.\n This warning can be ignored if is has been explicitely decided not to log changes.\n Except in this situation, make sure to add log changes.'
-            exit 1
-          fi
+      - name: Check for changes in changelog
+        env:
+          BASE_REF: ${{ github.event.pull_request.base.ref }}
+          NO_CHANGELOG_LABEL: ${{ contains(github.event.pull_request.labels.*.name, 'no changelog') }}
+        run: ./scripts/check-changelog.sh "${{ inputs.changelog }}"
+        shell: bash

scripts/check-changelog.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+set -uo pipefail
+
+CHANGELOG_FILE="${1:-CHANGES.md}"
+
+if [ "${NO_CHANGELOG_LABEL}" = "true" ]; then
+    # 'no changelog' set, so finish successfully
+    echo "::info no changelog label has been set"
+    exit 0
+else
+    # a changelog check is required
+    # fail if the diff is empty
+    if git diff --exit-code "origin/${BASE_REF}" -- "${CHANGELOG_FILE}"; then
+        >&2 echo "::warning Changes should come with an entry in the CHANGELOG.md file. This behavior
+can be overridden by using the \"no changelog\" label, which is used for changes
+that trivial / explicitely decided not to need a changelog entry."
+        exit 1
+    fi
+fi